132 GASTROCOPTA, MASCARENE ISLANDS, ETC. 



type locality being "on old walls near Port Louis, Mauritius." 

 He recorded it also from Bourbon, from Morelet's collection. 

 As von Martens had not seen types or topotypes of Nevill's 

 species, the identity of Nevill's Mauritian and von Martens' 

 Seychelles species is hypothetical. The question of identity 

 is academic, since Nevill's P. microscopica was never defined. 

 The species from Praslin, Seychelles, mentioned by Nevill as 

 Carychium n. sp. in Proc. Zool. Soc., 1869, p. 65, was subse- 

 quently described by him as Vertigo praslinensis. 



Von Martens' figures are copied, pi. 23, figs. 13-15. 



Some doubt may be entertained as to whether B. micro- 

 scopica is more than a local race of G. seignaciana. It differs- 

 by having somewhat larger teeth, especially the lower palatal 

 and basal. 



Specimens from Mauritius, collected by Dupont, and out 

 of the Morelet collection, are before me. They are cinnamon- 

 colored, fading towards the summit. Some have a weak, 

 rounded crest behind the outer lip, others none. As in several 

 American species, this character varies individually. The 

 angulo-parietal lamella is of the same shape as figured for B. 

 seignaciana. Lower palatal plica longer and reaching farther 

 in, also stronger. Basal plica well developed in all specimens. 

 Length 2.6, diam. 1.05 mm. (pi. 23, fig. 8). Length of small- 

 est specimen 2.3 mm. 



The teeth are slightly stronger than in G. servilis. This is 

 apparently the form which Crosse at one time referred to his 

 P. licnardiawa, as the specimens in the collection from Dupont 

 were so named. He subsequently omitted the locality Sey- 

 chelles. 



77. GASTROCOPTA LIEN ARDIANA (Crosse). PI. 23, figs. 9, 10. 



Shell perforate, oblong-ovate, smooth, thin, translucent, 

 slightly shining, corneous. Spire terminating in an obtuse, 

 rounded apex; suture impressed. Whorls 5, rather flat, the 

 last a little shorter than the spire, rotund at base. Aperture 

 subvertical, rotund-lunar, two-toothed within; peristome 

 simple, very slightly expanded, whitish, the margins separ- 

 ated, converging ; parietal margin having a lamelliform, 



